This is what i do :
I use my wheel cleaner, or even a multipurpose cleaner, 2 got scrubbing brushes, 1 thick and heavy duty one, and one finer one. And a bucket of water with car wash in it.
Get out in the sunlight (as rare as it is in the UK) and scrub till no brown is left. Rinse as often as possible, rotate the wheels as well so you have no patches left.
Then dress.